Americans for Prosperity — a group backed by industrialists David and Charles Koch spending millions of dollars on political races nationally — has jumped into a local election in northern Wisconsin by attacking opponents of a proposed iron ore mine.

The group's Wisconsin organization mailed fliers to voters in Iron County, identifying seven candidates challenging Iron County Board incumbents as "anti-mining radicals," in advance of the April 1 election.

The mailing claims the county is "being targeted by wealthy environmental groups from outside Wisconsin," and says opponents of mining "do not care if our stores close and our families go on welfare."

Gogebic Taconite is proposing to construct a $1.5 billion iron ore mine in both Iron and Ashland counties. The project has bitterly divided environmental and business interests, especially during the fight over new mining regulations friendly to Gogebic that passed the Legislature in 2013.

But considerable attention has shifted to the proposed mining site on private forest land, where Gogebic has an option on mineral rights.

A small group opposed to the project has camped nearby, and the Iron County Board two weeks ago voted to remove the group from the camp. The board and county officials also still must negotiate with Gogebic over a zoning agreement that would regulate mining activity.

One of the candidates targeted is Victor R. Ouimette, a retired insurance broker and president of the Mercer Chamber of Commerce.

"I have a hard time understanding why the Koch brothers think I am such a threat to their well-being — that they single me out in poor little Iron County?" Ouimette said.

David Fladeboe, state director of Americans for Prosperity, said that "the mining issue has been a big one for us. It's not just been an issue fought at the state level, but also at the local, and we wanted to talk about it."

Fladeboe said his group mailed about 1,000 brochures to county residents, identifying challengers they say are opposed to the mining project. He said the group has one more mailing planned that will tout candidates supporting the mine.

Americans for Prosperity has been a dominant force in recent elections. In the 2012 Wisconsin U.S. Senate race, the group spent $1.4 million against Democrat Tammy Baldwin, according to the Center for Responsive Politics, using data from the Federal Election Commission.

Koch Industries Inc. has business interests in Wisconsin, including a Georgia-Pacific plant in Green Bay.

Fladeboe said the group's reference to "wealthy environmental groups from outside of the state" referred to organized protest activities near the mine site and the presence of a group occupying a "harvest camp," across Highway 77 from the mining site.

The harvest camp has had strong involvement by members of the Lac Courte Oreilles band of Lake Superior Chippewa. Protest activities last summer included an attack and vandalism of some Gogebic workers that protesters videotaped and later posted on Earth First! Newswire.

Ouimette said it's inaccurate to label him as a mining opponent. He joined other local residents in lobbying legislators to rewrite mining regulations giving Gogebic more certainty that the regulatory process wouldn't drag out for decades as it did with zinc and copper mines proposed near Crandon.

But Ouimette took a dimmer view of the project after Gogebic and Republican lawmakers advanced a mining bill that, in his view, weakened protections for wetlands and public waters.

"Mining isn't my primary interest in running," he said. Rather, Ouimette got into the race because he felt county officials were mismanaging a senior center in Mercer.

Another candidate being targeted, Richard A. Thiede, is a retired businessman who writes a blog that has been critical of the project.

Thiede has been critical of efforts by county officials to remove the protesters from the harvest camp. He said Gogebic's refusal to acknowledge that asbestos-like rock has been found on the site also has troubled him.

His campaign expense so far has been four rolls of stamps.

"There is no anti-mine cabal up here," Thiede said. "I'm just curious why they are spending the money up here."

About Lee Bergquist

Lee Bergquist covers environmental issues and is author of "Second Wind: The Rise of the Ageless Athlete."